After all my problem with rebuild engine I found that grinding shop who grind bore, made mistake and now it it not cylinder it is look like egg, so I need to start from start again,
this my previous thread regarding this engine problems: https://www.performancetrucks.net/fo...10#post4518210


After some suggestion from this forum (thanks to all) I found out that it better to buy new crankshaft and flywheel along with damper, so it is all balanced internal, the are nobody in my location who can balance factory crankshaft..

So I need to grind again for more bigger size to make cylinder not look like egg , so what is the safe size? I mean I seen some guys grind till 418, but not sure that is ok for engine, i was thinking something about 408

So here are the questions:
1. which size of bore you will made if you have LQ4 with supercharger on it? what is the safe bore size? which will not brake engine after years?

2. If you have a lot of money which brand you will buy of complete rotating assemblies...cast or 4340 ? I was thinking to buy the best HEAVY DUTY camshaft available on market, along with pistons, flywheel and damper, so it all balanced, and i will only bolt in a engine.. so all of it will be balanced and engine will not have any vibrations because of balance

3. after all this done do I need to flash ecu? because of mine new bore size?

4. what else you would change in engine ? in my previous thread you can find list off parts I bought , maybe it something more what i need to buy

 

You should have the shop that screwed up the bore, fix EVERYTHING. Your parts list was a nice 370, make them fix it and have them pay for it!

You don't need a new flexplate and pulley, these items DO NOT BALANCE the crankshaft! These engines are internally balanced!

Here is the link to one of the site's sponsor: http://www.texas-speed.com/shop/listcatsM.asp?MID=5

Where are you located? Someone needs to stick a foot in your machinist ***.

 

I understand having issues finding knowledgeable machine shop’s or mechanic’s in general where your located and then costs are inflated to boot, and what I’m going to tell you, I’m sure you’ve already thought about. If I were under the same conditions you are, I would at bare minimum purchase a complete assembled short-block, where all you have to do is install the heads and dress out the motor. If you have the coin and now even question the machine work on the heads as well, I would have to seriously consider purchasing a complete motor. I know it must be expensive to have a complete motor shipped to you and I completely understand wanting to save money by re-using what you can, but if you can’t trust the work your having done, you are likely to just keep throwing good money after bad and will end up costing you more in the long run.

 

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Listen to the advice given..Here are a few facts for you..
-The c.i.d is not only from bore..but from the stroke of the crank (Guy's are not "grinding" to 408 or 418...they bore/stroke to those c.i.d
-Safely a LQ4 can be bored to 4.030"..which wont "break" engine after years
-All camshafts are "heavy duty" just the grind varies
-ANY of the brands are sponsors carry are good,with Eagle probably being the cheapest
-Your machine shop SUCKS..
As stated above, save your money and buy an assembled shortblock and possibly heads,then have a reputable mechanic assemble/install..
-Get Blackbear to send you a NEW retuned PCM
Good luck!!
EDIT: I just read your orig thread...KEEP IT SIMPLE..only do a few things at a time

 

Thanks guys for you help,

After all your suggestion I decide to buy complete unit, because been in grind shop again, after they check the told that those cylinders was grind right, we checked ring it was again welded on pistons, so it look like the pistons was working with out oil and it welded themselves to rings, basically nobody can not tell me what the problem is, how the new rings and piston after several hours working can be welded to each other themselves, the other side working properly, actually same problem I had before, when we take out engine for rebuild on same side of engine was same problem with ring and pistons, we grind and put everything new, now it is same problem back again, anyway now I would like to buy complete unit, http://texas-speed.com/shop/item.asp?itemid=686 but as I`m really not good in engines, I want you guys to suggest me which options I can pick up to work well with my supercharger and my bad fuel in country.. and what should be pistons head flat top or -16cc or less..to work good with my supercharger i think supercharger should work fine with factory compression which is 9:1, please guys help me with option so I can place order, there are nobody professional in my country we locating far from USA, we 3000mil away from Turkey

 

Thanks a lot for your answer


After getting complete assembly and I will install my charger and everything ready, i need Blackbear to send me new PCM, ? Do i need to give them all engine details and charger details so they can sell me new PCM?

 

Yessir, they will need to know your entire setup...do you have a BlackBear tune already and just need a retune, or are you starting from scratch? When you order the PCM, there will be a list of questions about your truck for you to fill out, including engine, trans, mods, cam, heads, efans, tire size, gear ratio, etc. They also offer a scan cable tune where Justin sends you a cable that goes from your laptop to the OBDII port, and you download a free version of EFILive and log your truck, then send him the logs to make the proper adjustments. If it's a new engine and the truck isn't running, he'll have to send you a PCM with a base tune first though so you can get it running and drive and log it

 

You said this happened for a second time. So twice the rings & pistons welded to each other & on 2 separate builds? Were ring gaps spec'd properly? I'm no engine builder, & someone more versed than me in High Performance rebuilding may chime in, & say what gap shoulda been there.

Also, were your pistons anything special, or what pistons were they?

If running boost or nitrous, a piston w/. more material above the top ring is a safety factor. Extra heat / pressure generated from forced induction will be less likely to create issues w/. rings on pistons designed for FI (forced induction).For instance, Lunati offers 4032 or a 2618 alloy depending on your needs (as in N/A or FI).

Again, maybe a person more knowledgable than me in this like budhayes3, 1 Bear or KBRacing to name a few sharp guys will comment on my next bit, so this could be incorrect. Failure could come from a variety of factors like I listed. In addition, I believe timing, tuning, compression ratio, gas used, etc. I'd even look at oiling, cause somthin caused a lack of oil flow. Granted some of these are questions / statements from somethin u may not have to worry about, since you're not reusing your old build. It's just things I wonder about.

If I'm misinformed, someone please correct me on any bad info.

 

Since I don't rebuild engines, I have to go by what I see put in builds for hard parts & refine from there w/. my preferences. 3 main components of the rotating assembly (crank, pistons, rods) & brands I'd pick if I do a ***** out LS build. Others may have different ideas or preferences.

-Crank: stock LS has a good reputation to hold up to abuse. Also, Callies & Lunati.
-Pistons: some good forged stuff. In no order, Diamond, CP, JE/SRP, Lunati, Mahle.
-Rods: Oliver, Lunati, Howards, Crower.

I may've forgotten one, but I think these are some choice products.

I'd upgrade rods & pistons before I'd spend on crank.
BTW, what supercharger u running again?

 

Thanks a lot for your help,


Regarding issue i having actually nobody can explain me,

first time i diced to rebuild engine because it has some kind of power lost, so I decide to rebuild it, when we open the engine it passenger side all 4 pistons was welded to rings, we order new pistons ring and all other parts, we install everything let engine work some 2-4 hours, then we check compression it was 2-3 bar that mean nothing in all that 4 pistons from passenger side, other 4 cylinder from driver side was working good, and have 9-10 bar compression, we reopen engine, again same issue, new piston and ring was welded to each other again, 2 different grinding shop checked all cylinders they was fine, only new rings on that passenger side is damaged cylinders, it was look like that passenger side cylinder was working with out oil, and water, we checked all tunnels they all ok, the water pump and oil pump is new one and 15% better flow than originally, so nobody can not tell, what to do, if after rebuild all parts same how can one side work perfect, and other side will not work at all,so all this make me complete dead

Pistons are manley brand, with coating on them, you can see pictures...

BTW which pistons tops is best for my engine which use magnacharger on it-29cc or -16cc, or any other one, please guys advice

supercharger is http://www.magnacharger.com/pdf/manual-HummerH2.pdf